Method of drawing glass.



R. S. PEASE;

METHOD OF DRAWING GLASS.

APPLICATION FILED JUNE 28, 1912. 1, 16 Patented Apr. 20, 1915. ssums-sum 1.

I TTORNE NJ WITNESSES:

R. S. PEASE.

METHOD OF DRAWING GLASS. APPLICATION FILED JUNE 28, I912.

Patented Apr. 20, 1915.

3 SHEETS-SHEET 2.

[llllll WITNESS.-

ATTORNEY.

R. S. PEASE.

METHOD OF DRAWING GLASS. APPLICATION FILED JUNE 28, 1912.

Patented Apr. 20, 1915.

3 SHEETS-SHEET 3.

/ ATTORNE 'nnrrnn stratus rarnn r ora ion.

EUGER S. IPEASE, F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE PITTSBURGHFLATE GLASS CQMPANY, 0F PITTSBURGH, PENNSYLVANIA, A CORPORATION 01:"

PENNSYLVANIA.

insects.

METHOD OF DRAWING GLASS.

. Patented Apr 2% 1911.5.

Application filed June 28, 1912. Serial No. 706,528.

' burgh, in the county ofAllegheny and State of Pennsylvania, haveinvented certain new and useful Improvements in Methods of DrawingGlass, of which the following 1s a specification.

This invention relates to a method. of and apparatus for drawing glass,and has for its primary objects the provision of an improved methodofdrawing glass in flat or sheet form; the provision of an improvedmethod of. drawing glass wherein a tubular member is compressed intoflat form, the operation being continuous in character; the provision ofan improved method of drawing window glass and annealing it as it isbeing drawn; the provision of an improved arrangement of annealing leer;and in general, the provision of improved apparatus for carrying out themethod described. These, together with such other "objects ashereinafter appear or are incidental to the invention, I attain by meansof a construe tion which I have illustrated in preferred form in theaccompanying drawings,

' wherein:

Figure 1 is a section through a tank extenhouse showing an application Ision or dog of my improved apparatus and the formation of a sheet ofglass; Figure 2 is a similar section through a slightly modified form ofapparatus; Fig tion through my improved form of leer;

Figure 4; is a side elevation of the bait employed; Fig. 5 illustrates asectional view of the bait and diagrammatically illustrates the movemtmtof the bait in the initialdrawing operation; and Fig. 6 is a sectionthrough a preferred form of conveyer belt used in connection with myapparatus; Fig. 7 is a section through a detail of my invention,

In carrying out my invention, I'propose to draw a tubular member fromthe body of molten glass and press together the sidesof the tubularmember in the form of a sheet, the sheet so formed being drawn throughan annealing leer, thus in efiect constituting the process a continuousone.

Referring to Figure 1, of the drawing, it will be seen that I haveillustrated in cross section a dog-house or furnace extension 1-,

which a tubular member 3 is drawn by from having 8is a longitudinal sectom of the dog-h0use, the cavity 5 of the.

core being closed at the bottom by a plate and opening at the top abovethe level of the glass. Air from any suitable source is supplied bymeans'of the pipe 6 which opens into the cavity 5. In order to shut, 0dthe heat and flames in the dog-house from the tubular member beingdrawn, I provide an air dra Wing ring 7 which is provided with anannular recess 01', groove 8 adapted to re ceive the ends ofthepedestals 9 which are provided with airports or passages 10. I

These air ports or passages, as will clearly their upper ends into thecavity 8v and at their lower ends to a pipe 11 which leads to anysuitable source of air supply. When a tubular member is to be drawn, airpressure appear from inspection of'Fig. 1, open at i is admitted to thecavity or recess,8 through the ports 10 and the drawing ring is therebyelevated until it comes in contact with the top-stone of the dog-house,thus preventing the heat-and flames of the dog-house access to thetubular member being drawn. It will be noted that the pedestals are alsoremovably mounted in the bottom of the do house, asbestos packing 12being provided .or the standard *5 and the pedestals. The standard 5.isof an extended flatshape as will-appear from inspection of Fig. 7, andthe bait 4; isofsimilar configuration so that itmay be immersed in theglass about the standard. The tubular member 3 is drawn in the usualmanner by partially immersing the bait in the glass in the dog house andthereafter elevating it, air being supplied to the interior of thetubular member formed through the pipe 6 of the cavity 5 as hereinbeforeset forth.

The apparatus for compressing the tubular member into sheet form willnow be described. Mounted on tracks 13 on the top of thedog-house arearpair of oppositely disposed carriages 14: and 15, each of which isprovided with a pair of rolls 16 which carry conveyer belts 17. Thebelts are tightened by any preferred means of belt tighteners 18 and aredriven by means of motors 19, the beltsbeing driven in oppositedirections as .indicated bythe arrows 1n Fig. 1. The car- TIME Ilti.

' with a pair of rolls 23 which carry a conveyer belt 24, the rolls andbelt 24, when in operative position, being adapted to bear against thesheet 3 as indicated in Fig. 1. The carriage 21 is driven by a motor 25and the conveyer 24 is driven through one of the rolls by means of themotor 26.

The operation of the apparatus thus far described is as follows: Thecarriage 15 is moved to the left a sufiicient distance to permit of themovement of the carriage 21 in the same direction a suflicient distanceso that the bait 4 will clear as it is being lowered to the drawingorifice 2. The bait is preferably supported on the conveyer belt 17 ofthe carriage l4, or.may be supported from above, as desired, as it isbeing lowered into the dog-house, the carriage 14 being retracted sothat the bait, as it moves downward, will embrace the standard 5. Thebait is then elevated and the tubular member 3 is drawn, the bait beingraised a sufficient distance to clear the carriage 14 which is thenadvanced to the position shown in Fig. 1, after which the bait is movedto the right in a manner hereinafter to be described, and deposited onthe belt 17 of the carriage 14. The carriage 21 is then moved tooperative position, after which the carriage 15 is advanced to theposition indicated in Fig. 1, at which time the rolls 16 will compressthe tubular member into sheet form. It is to be observed that while therolls 16 are the positive means for compressing the tubular member, thesaid member is compressed immediately between the conveyer belts 17which are driven at the same rate of speed as that at which the baitmoves.

The carriage 14 is provided with a copper plate 27 which is providedwith a plurality of pipes 28 towhich steam or other suitable heatingagent is supplied in order to prevent the cooling of the. sheet 3 beforeit is carried into the annealing leer. The plate 27 serves theadditional purpose of providing a platform or. su port for the belt 17when the sheet 3 is eing flattened or smoothed out by the block 29which, when the occasion therefor arises, is moved back and forwardacross the sheet 3 and flattens out any irregularities therein. Theblock 29 is preferably composed of bass-wood boiled in a saturatesolution of borax, which, when so treated, chars but does not readilyburn with a flame, and has been found most suitable for the purposeindicated.

In order to maintain a uniform pressure within the tubular member 3 asthe drawing operation continues, I provide in addition to the air supplypipe 6, an outlet pipe 6 which leads from the cavity 5 in the standardto the exterior of the dog-house and is provided with a suction fan 30,three-way cook 31 and an automatic relief valve 32. In normal operation,the fan 30 is not driven and the three-way cock 31 is turned toestablish communication between the pipe 6 and the valve 32, the valvebeing set so as to maintain a uniform pressure within the tubular member3. If desired, the three-way cock may be turned to cut out the reliefvalve 32 and vent the pressure in the pipe 6 through the pipe 34, thesuction fan 30 being driven in such case so as to cause a circulation ofair through the pipe 6, the tubular member 3 and the pipe 6 to theatmosphere.

Referring to the Figure 3, it will be seen that I diagrammaticallyillustrate anannealing leer 35, which may be of any preferredconstruction but which is preferably provided with a plurality oflongitudinally extending heating flues 36 beneath which are locatedcorresponding chambers filled with storage material 37, such, forexample, as broken brick and sand, the depth decreasing toward the coolor discharge end of the leer. This arrangement secures proper graduationof the temperature through the entire length of the leer. Heat isapplied to the flues 36 by means of burners located at 38. The leer islocated immediately adjacent the dog-house and the sheet 3 is carriedfrom the conveyer belt 17 of the carriage 14 to a conveyer mechanismcomprising a plurality of oppositely disposed conveyer belts. The lowermember of the conveyer mechanism is preferably composed of but one belt39, but may be composed of two or more belts, as found most suitable.The belt 39 is'carried on rolls 40 and 41, the bearing for the roll 40being movable longitudinally in order that the belt may be tightened.The roll 41 is driven by means of the motor 42 and worm 43. Locatedbetween the rolls 40 and 41 are a plurality of idler rolls 44. Theupperconveyer member is preferably divided into sections, each sectioncomprising a pair of rolls 45 which carry a conveyer belt 46. The rollsare carried in a suitable frame-work 47 mounted in the leer for verticalmovement as clearly indicated at the left hand of Figure 3. Previous toa drawing operation, all of the upper sections are-moved to thepositions indicated in dotted lines so as to permit the passage of thebait as it is being moved along with the lower conveyer belts, thesections being lowered successively as the bait passes through 25carried into the leer as previously pointed the leer until the belts 46engage the upper surfaceof the glass sheet 3'. Thesheet is thussubstantially inclosed and protected from any draft of air in theannealing leer the presence of which would result in breakage of thesheet.

At the discharge end of the leer, the sheet is fed onto a link-beltconveyer 48, the links of which are provided with transversely disposedtread members 49 which serve as supports on which the sheet may be cutinto sections.

Referring to Fig. 5 it will be seen that T have diagrammaticallyillustrated the relation of the bait and carriage 14 with respect toeach other during the initial drawing movement. The bait 4 is providedwith trunnions 50 which engage the tracks 51 preferably composed ofchannels the flanges of which serve to guide the trunnions as the baitis being elevated by the cable 52 .or other suitable elevatingmeans. Thebait is elevated a suflicientdistance to clear the carriage and rollsand is then moved to the right and deposited on the belt 17 and thenout.

In Fig. 6 l have shown a preferred form of conveyer belt comprising acopper body member 54 and a covering sheet 53 of asbestos or similarrefractory material. This construction gives a uniform and rapiddistributionr, of heat and-provides a suitable surface upon which tocompress the tubular member.

Assuming that the tubular member 3 is being drawn and compressed as thedrawing operation continues, the flattened glass is carried on the belt17 of the carriage 14 over" the plate 27 where it is supplied with heatiand is flattened and smoothed out if necessary by the block 29. It isthen gradually carried through the leer 35 between the oppositelydisposed conveyer belts where it is substantially out of contact withthe atmosphere. By the time it reaches the discharge end of the leer theglass has become annealed and is cut on the link belt conveyer 48.

One of the chief advantages of my invention is the reduction in the costof production which results not only from the continuous character ofthe operation but also from the fact that the drawing and the annealingof the glass are practically one operation, thus dispensing withfrequent handling of the glass. The apparatus is simple and the feetageof glass obtained is greatly increased.

Tn Fig. 2 T have illustrated a slightly modified form of apparatus. Inthis case the carriage 15 is dispensed with and the tubular member iscompressed between the belts of the carriages 14 and 21.

It will be understood that T have but diagrammatically illustratedapparatus for carrying out my invention and that other- "forms ofmechanism can be employed without departing from the spirit thereof.Other advantages will readily occur to those skilled in the art.

Having thus described my invention and illustrated its use, what I claimas new and desire to secure by Letters Patent is the following V 1. Theherein described process of making sheet glass which consists in drawinga tubular member from the body of glass and in-compressing said memberas it is being drawn into sheet form.

2;, The herein described process of making sheet glass which consists indrawing a tubular member from a body of glass, in

compressing the tubular member to form a sheet at a predetermineddistance from the body of glass, and in maintaining a uniform airpressure within the tubular member.

3. The herein described process of making flat glass articles whichconsists in. drawing a'hollow article and in compressing the article toform a sheet.

4. The process of making a glass sheet, which consists in continuouslydrawing a cylinder of glass and continuously forming the cylinder into aflat sheet as the drawing progresses.

In testimony whereof T have hereunto signed my name in the presence ofthe two subscribed witnesses.

